Method of communication between mobile station and base station in mobile communication system

ABSTRACT

Method of communication between a mobile station and a base station in a mobile communication system of IMT-2000 communication network basis, which is suitable for effective transmission of various multimedia information within a given channel capacity, the method including the steps of (1) when a mobile station receives a data transmission request, providing one portion of a period of a data frame with regular number and arrangement of down link slots and up link slots and the other portion of the data frame with irregular number and arrangement of down link slots or/and up link slots depending on characteristics and amount of subscriber data to be transmitted, (2) determining a transmission type according to which a communication is executed using a competition period for determining priorities of the subscriber data, a reservation period for making a reservation for time slots for use in transmission of the subscriber data, and an assignment period for assigning a memory period according to an amount of the subscriber data, which periods are selectively and respectively included in the one portion of the data frame and in the other portion of the data frame, and (3) providing the data frame according to the transmission type and transmitting to the base station.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of co-pending application Ser. No.10/641,302 filed on Aug. 15, 2003, currently pending, which claims thebenefit of application Ser. No. 09/280,849 filed on Mar. 30, 1999, noU.S. Pat. No. 6,614,778 B1 issued on Sep. 2, 2003, which claims thebenefit and right of priority to Korean Patent Application No.11671/1998, filed on Apr. 2, 1998. The contents of all applications areincorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method of communication between amobile station and a base station in a mobile communication system, andmore particularly, to a method of communication between a mobile stationand a base station in a mobile communication system of IMT-2000communication network basis, which is suitable for effectivetransmission of various multimedia information within a given channelcapacity.

2. Background of the Invention

In general, there are bidirectional transmission and unidirectionaltransmission in signal transmission between a base station and a mobilestation in the mobile communication system. In the bidirectionaltransmission, a plurality of forward time slots and backward time slotsare alternatively assigned to a communication channel establishedbetween the mobile station and the base station, for transmission ofdata in time slot units assigned to a same time. The time slot means atime interval of information transmission on the communication channel.In the present invention, the time slot for use in informationtransmission from the base station to the mobile station is called asdown link slot, and the time slot for use in information transmissionfrom the mobile station to the base station is called as an up linkslot.

FIG. 1 illustrates an architecture of down link slots and up link slotsof a bidirectional communication in a related art mobile communicationsystem.

Referring to FIG. 1, data frames are transmitted in a forward orbackward direction during time slots S1˜S4 assigned in advance. That is,the data frames are transmitted between the mobile station and the basestation continuously alternating the down link slot S1 and S3 and the uplink slots 52 and S4. That is, the data frames produced at the basestation or the mobile station are transmitted repeatedly alternatingassigned down link slots and up link slots. This type of signaltransmission has been developed on the assumption that the mobilecommunication network serves for a speech data transmission in which aratio of data transmission between a transmission side and a receptionside is 1:1. Due to this reason, a trend is kept on, in which the downlink slots and the up link slots are assigned simply at an equal ratioto most of current mobile communication devices. However, in a mobilecommunication service of IMT-2000 communication network basis, not onlyspeech services, but also a variety of multimedia services, such asinternet service and image broadcasting service are provided. In theinternet or image service, an asymmetric transmission system isemployed, in which an amount of data is transmitted in down link slotsis relatively greater than an amount of data transmitted in up linkslots, resulting to use slots of one direction of the down or up linkslots continuously while slots of the other direction are almost notused in a case the multimedia service is given using a communicationnetwork having the down link slots and the up link slots assignedequally. In such a case, there is a problem that a capacity of a givenchannel is not used effectively. Consequently, to match to such anasymmetric transmission system, a TDD (Time Division Duplex) system issuggested, in which different numbers of down link slots and up linkslots are assigned. That is, numbers of down link slots and up linkslots are varied with amounts of data.

However, the TDD system has many problems in practical applications. Thegreatest problems are that random access and synchronization acquisitionare difficult because periods of the mobile station and the base stationwhich have regular down link slots and up link slots are not known inadvance when the mobile station attempts to start an initialcommunication. In order to solve such problems, as shown in FIG. 2, animproved TDD system is suggested, which employs both a static period(TDD1) having down link slots and up links slots assigned therein in aregular alternation and a dynamic period (TDD2) having down link slotsand up link slots irregularly assigned therein according to amount ofthe data to be transmitted. In the improved TDD system, the problems ofrandom access and the synchronization acquisition between the mobilestation and the base station can be easily solved by using the staticperiod (TDD1). And, since a communication can be made by providingnumbers of down link slots and up link slots in the dynamic period(TDD2) varied with an amount of data, a given channel capacity can beused, effectively.

Thus, the static period (TDD1) in which the down link slots and the uplink slots are assigned alternatively is provided for solving theproblems in random access and synchronization. However, there are nosuggestions on standards or techniques which improve an efficiency ofgiven channel capacity in cases when numerous subscribers require callsor hand-off almost at a time in a city center where many offices areconcentrated or a business quarter where many people gather. Therefore,there is no appropriate way to solve the problem when a number of callor hand-off required on the same time exceeds the given channelcapacity. Accordingly, a technique in need, which can maximize anefficiency of a given channel source in a case when there is anexcessive number of call or hand-off requirements in the IMT-2000communication network in which the multimedia service is provided.

SUMMARY OF THE INVENTION

Accordingly, the present invention is directed to a method ofcommunication between a mobile station and a base station in a mobilecommunication system that substantially obviates one or more of theproblems due to limitations and disadvantages of the related art.

An object of the present invention is to provide a method ofcommunication between a mobile station and a base station in a mobilecommunication system of IMT-2000 communication network which can providea variety of communication services, which allows an effectivecommunication between mobile stations and abuse station when numerousmobile stations require communication services at almost the same time.

Another object of the present invention is to provide a method ofcommunication between a mobile station and a base station in a mobilecommunication system of IMT-2000 communication network which can providea variety of communication services, which can provide a data framestructure that allows easy determination of transmission systemdepending on characteristic and amount of data to be transmitted whennumerous mobile stations require communication services at almost thesame time.

Additional features and advantages of the invention will be set forth inthe description which follows, and in part will be apparent from thedescription, or may be learned by practice of the invention. Theobjectives and other advantages of the invention will be realized andattained by the structure particularly pointed out in the writtendescription and claims hereof as well as the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the present invention, as embodied and broadly described, the methodof communication between a mobile station and a base station in a mobilecommunication system of IMT-2000 communication network basis, which issuitable for effective transmission of various multimedia informationwithin a given channel capacity, the method including the steps of (1)when a mobile station receives a data transmission request, providingone portion of a period of a data frame with regular number andarrangement of down link slots and up link slots and the other portionof the data frame with irregular number and arrangement of down linkslots or/and up link slots depending on characteristics and amount ofsubscriber data to be transmitted, (2) determining a transmission typeaccording to which a communication is executed using a competitionperiod for determining priorities of the subscriber data, a reservationperiod for making a reservation for time slots for use in transmissionof the subscriber data, and an assignment period for assigning a memoryperiod according to an amount of the subscriber data, which periods areselectively and respectively included in the one portion of the dataframe and in the other portion of the data frame, and (3) providing thedata frame according to the transmission type and transmitting to thebase station.

In another aspect of the present invention, there is provided astructure of a data frame for use in communication between a mobilestation and a base station in a mobile communication system, the dataframe having a static period having at least one or more than down linkslots and at least one or more than one up link slots, both assignedthereto regularly and alternatively and a dynamic period having downlink slots and up link slots, both assigned thereto irregularly, thestructure including a competition period for determining a priority ofdata to be transmitted from the mobile or the base station during eachof the static period or the dynamic period, a reservation period formaking a reservation for a slot for use in transmission of the data, anassignment period for assigning a memory period according to an amountof the data, wherein the competition period, the reservation period andthe assignment period are provided selectively.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and explanatory and areintended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings, which are included to provide a furtherunderstanding of the invention and are incorporated in and constitute apart of this specification, illustrate embodiments of the invention andtogether with the description serve to explain the principles of theinvention:

In the drawings:

FIGS. 1 and 2 respectively illustrate architectures of down link slotsand up link slots for use in a bidirectional communication in a relatedart mobile communication system;

FIG. 3 illustrates an architecture of down link slots and up link slotseach having a competition period, a reservation period and an assignmentperiod in a data frame in accordance with a preferred embodiment of thepresent invention;

FIG. 4 illustrates an architecture of data frame transmitted through anup link slot in accordance with a first preferred embodiment of thepresent invention;

FIG. 5 illustrates an architecture of control frame transmitted throughan up link slot in accordance with a first preferred embodiment of thepresent invention;

FIG. 6 illustrates an architecture of data frame transmitted through adown link slot in accordance with a first preferred embodiment of thepresent invention; and,

FIGS. 7 and 8 illustrate a flow chart showing a communication procedurebetween a mobile station and a base station in accordance with anotherembodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the preferred embodiments of thepresent invention, examples of which are illustrated in the accompanyingdrawings. FIG. 3 illustrates an architecture of down link slots and uplink slots each having a competition period, a reservation period and anassignment period in a data frame in accordance with a preferredembodiment of the present invention.

Referring to FIG. 3, the data frame in accordance with a preferredembodiment of the present invention includes a static period (TDD)) anda dynamic period (TDD2) each having a competition period 10 and 40 fordetermining priorities of subscriber data, a reservation period 20 and50 for making a reservation for time slots for use in transmission ofsubscriber data, and an assignment period 30 and 60 for assigning amemory period according to an amount of subscriber data. In each of thecompetition period 10, the reservation period 20, and the assignmentperiod 30 in the static period (TDD1), there are pluralities of downlink slots and up link slots assigned therein in a regular alternationfor representing characteristics of a data to be transmitted, and ineach of the competition period 40, the reservation period 50, and theassignment period 60 in the dynamic period (TDD2), there are pluralitiesof down link slots and up link slots irregularly assigned thereinaccording to kind and amount of data to be transmitted. Here, a numberof slots assigned to each of the static period TDD1 and the dynamicperiod TDD2 in one data frame may vary under the control of an MAC(Medium Access Control) layer in the communication system. Thecompetition period 10 and 40, the reservation period 20 and 50 and theassignment period 30 and 60 may be provided selectively in the staticperiod (TDD1) and the dynamic period (TDD2) as necessary. If prioritiesare given to the competition period 10 and 40, the reservation period 20and 50 and the assignment period 30 and 60, the priorities are thereservation period, the assignment period and the competition period. Inthe channel for transmission of the foregoing data frame, there are PSCH(Packet Signal Channel), PDCH (Packet Data Channel) and PCCH (PacketControl Channel), which may be selectively provided to the reservationperiod, the assignment period and the competition period. The PSCH is achannel for transmission/reception of a signaling message intransmission of a packet data, the PDCH is a channel for directtransmission/reception of a packet data to be transmitted. The PDCH isalso used for requesting time slots for transmission of packets and fortransmission of data related to to the request. The PCCH is a channelfor use in transmission/reception of a control data for identifying thepacket data in transmission/reception of the packet data, and also usedin assigning time slots for transmission of the packet data and fortransmission of data related to the assignment.

FIG. 4 illustrates an architecture of data frame transmitted through anup link slot in accordance with a first preferred embodiment of thepresent invention.

Referring to FIG. 4, the data frame transmitted through an up link slotin accordance with a first preferred embodiment of the present inventionincludes an FI (Frame indicator) parameter 71 for representing a contentof data frame, a priority parameter 72 for representing a priority on adata frame processing, a prd (periodic) parameter 73 for representing aperiodicity or non-periodicity in requesting time slots, a COR (Contentof Request) parameter 74 for representing information related to anumber of required slots or a periodicity of slot request in requestingthe slots. The different parameters 71˜74 contained in the data frame 70may be removed, or another parameter may be added as necessary. As shownin FIG. 4, the data frames transmitted through the up link slot areassigned in octet units each with 8 bits. Of one bit assigned to the FIparameter 71, if the one bit is “0”, it represents that the data frameis a pure packet data, if “1”, it represents that the data frame is arequest for a packet data and a time slot. Of two bits assigned to thepriority parameter 72, if the two bits is “00”, it represents a dataframe of an initial transmission packet, if “01”, it represents a dataframe of a re-transmission packet, if “10”, it represents a data frameof continuous packets. Of one bit assigned to the prd parameter 73, ifthe one bit is “0”, it represents that the time slot request is periodicand if “1”, it represents that the time slot request is not periodic.And, a number of bits assigned to the COR parameter 74, representinginformation related to a number of required slots or a periodicity ofslot request in requesting the slots, may be varied.

FIG. 5 illustrates an architecture of control frame transmitted throughan up link slot in accordance with a first preferred embodiment of thepresent invention.

Referring to FIG. 5, there is a parameter (Ack of Received Packet DataFrame) 80 which represents confirmation of reception up to eight packetdata frames assigned to the control frame transmitted through the uplink slot. If a bit assigned to the parameter is “0”, it represents thata confirmation of reception is made, if “1”, it represents that aconfirmation of reception is not made. For example, if the parameter is“0100 1001”, it represents that a second, a fifth and a last packet dataframes are not received, properly.

FIG. 6 illustrates an architecture of data frame transmitted through adown link slot in accordance with a first preferred embodiment of thepresent invention.

Referring to FIG. 6, the data frame 90 transmitted through a down linkslot has total 8 bits assigned thereto and includes a control frameperiod 91 and a data frame period 92. The control frame period 91 has 2bits assigned thereto for selectively representing a frame on the downlink slot of being a packet data frame, a packet control frame, or amixed frame of the packet data frame and the packet control frame. Ifthe control frame period 91 is represented by “00”, it indicates thatthe frame on the down link slot is the packet data frame, if representedby “01”, it indicates that the packet frame on the down link slot is thepacket control frame, if represented by “10”, it indicates that thepacket frame on the down link slot is the mixed frame of the packet dataframe and the packet control frame.

FIGS. 7 and 8 illustrate a flow chart showing a communication procedurebetween a mobile station and a base station in accordance with anotherembodiment of the present invention.

Referring to FIGS. 7 and 8, each mobile station determines if there is arequest for data transmission from the subscriber at preset intervals(ST1). If there is the data transmission request from the subscriber asa result of the determination, the mobile station determines if thesubscriber data to be transmitted is a reservation transmission (ST2).If it is the reservation transmission as a result of the determination(ST2), reservation characteristics are determined (ST3). The reservationcharacteristics are a period and a size of a reserved slot.

However, if it is not the reservation transmission as a result of thedetermination (ST2), it is determined that a data to be transmitted hasa quantity that can be transmitted through one time slot (ST4). Ifimpossible, a number of time slots required for transmission of entiredata is determined (ST5). Thus, after determining the data to betransmitted in a reservation transmission, an assignment transmission,or a competition transmission, the mobile station forms a data frameaccording to a determined transmission type and transmits the data tothe base station (ST6 and ST7). Then, the mobile station determines ifthere is a response from the base station which have received the datatransmitted (ST8). In this instance, the base station determines ifthere is a data frame received from the mobile station during everycompetition period (ST9). If there is no data frame received from themobile station as a result of the determination in the determinationstep (ST9), the base station stands by the next competition period(ST10). However, if there is a data frame received from the mobilestation as the result of the determination in the determination step(ST9), the base station examines characteristics of the received dataframe. That is, the received data frame is determined of beingtransmitted in a reservation transmission (ST11). If it is atransmission in the reservation transmission, the reservationtransmission is started (ST12), and if not, the received data frame isdetermined of being transmitted in an assignment transmission (ST13). Ifit is the assignment transmission as a result of the determination step(ST13), a remained data is transmitted through an assigned slot and anidle state is restored. However, if it is not the assignmenttransmission as a result of the determination step (ST13), the idlestate is restored, directly.

As has been explained, the method of communication between a mobilestation and a base station in a mobile communication system of IMT-2000communication network basis that provides a variety of multimediaservices having speech signals and image signals composited thereinallows an effective transmission of data according to a transmissiontype determined according to service options for the mobile station.Therefore, a communication service can be provided, in which a givenchannel capacity can be maximized even in a case when subscribers to themobile stations within a certain region request for data transmission atsubstantially the same time.

It will be apparent to those skilled in the art that variousmodifications and variations can be made in the method of communicationbetween a mobile station and a base station in a mobile communicationsystem of the present invention without departing from the spirit orscope of the invention. Thus, it is intended that the present inventioncover the modifications and variations of this invention provided theycome within the scope of the appended claims and their equivalents.

1-17. (canceled)
 18. A method for transmitting a data frame and acontrol frame transmitted from a mobile station to a base station viauplink, the method comprising: transmitting the data frame to the basestation at one transmission opportunity, wherein the data framecomprises a header portion and a data portion, and wherein the headerportion comprises: a first field to indicate to the network whether ornot the data frame has a time resource request while data in the dataportion is transmitted simultaneously, the first field having either afirst logic value or a second logic value, the first field having thefirst logic value when the data frame has the time resource request, anda second field to contain an amount of time resource required when thefirst field has the first logic value; and transmitting the controlframe to the base station, wherein the control frame has anacknowledgement field indicating a reception status of a plurality ofdata packets from the network at another transmission opportunity. 19.The method of claim 18, wherein the acknowledgement field comprises abitmap, each bit of the bitmap indicating whether the corresponding datapacket among the plurality of data packets is successfully received ornot.
 20. A mobile station for transmitting a data frame and a controlframe to a base station via uplink, the mobile station comprising: adata frame generator configured to form the data frame, wherein the dataframe comprises a header portion and a data portion, and wherein theheader portion comprises: a first field to indicate to the networkwhether or not the data frame has a time resource request while data inthe data portion is transmitted simultaneously, the first field havingeither a first logic value or a second logic value, the first fieldhaving the first logic value when the data frame has the time resourcerequest, and a second field to contain an amount of time resourcerequired when the first field has the first logic value; a control framegenerator configured to form the control frame, wherein the controlframe has an acknowledgement field indicating a reception status of aplurality of data packets from the network; and a transmitter fortransmitting the data frame and the control frame to the base station atdifferent transmission opportunities from each other.
 21. The mobilestation of claim 20, wherein the acknowledgement field comprises abitmap, each bit of the bitmap indicating whether the corresponding datapacket among the plurality of data packets is successfully received ornot.